WO2010089716A1

WO2010089716A1 - Dispensing device for dispensing a liquid gas formulation in a metered manner and method for producing the dispensing device

Info

Publication number: WO2010089716A1
Application number: PCT/IB2010/050535
Authority: WO
Inventors: Gerhard Obrist
Original assignee: Illinois Tool Works Inc.
Priority date: 2009-02-06
Filing date: 2010-02-05
Publication date: 2010-08-12
Also published as: DE102010006944A1; AU2010212001B2; GB2467836A; DE102010006944B4; EP2393730B1; EP2393730A1; US20120024911A1; JP2012517565A; GB2467836B; US9038864B2; AU2010212001A1; TW201040432A; CH700392B1; GB201001883D0; CN102348613A; KR20110116159A; CA2751710A1; CH700392A2

Abstract

The invention relates to a device for dispensing a liquid gas formulation in a metered manner, wherein the device is particularly suited for use as an injection system in nail driving devices and comprises a pressure-stable container (1) having a flanged rim (2), to which a valve cover (3) containing a dispensing valve (4) is tightly fastened. The container (1) is equipped with two separated chambers (6,7), one of which receives the liquid gas formulation (F) and communicates with the dispensing valve (4) and the other of which contains a driving medium (L) under over-pressure. A piston (5), which can be moved in a sealing manner and which divides the container into the two chambers (6,7), is provided in the container (1). The driving medium (L) is compressed air in combination with a small amount of liquid gas formulation (F_ü). The flanged rim (2) of the container (1) is designed as an inner flanging. The piston (5) is equipped with a one-way valve arrangement, which allows liquid gas formulation (F) to overflow from the chamber (6) containing the liquid gas formulation (F) into the chamber (7) containing the driving medium (L, F_ü). The dispensing device is particularly inexpensive to design and can be cheaply produced and filled in a very simple manner.

Description

DISTRIBUTION DEVICE FOR THE DOSED DELIVERY OF A LIQUID GAS FORMULATION AND METHOD FOR THE PRODUCTION THEREOF

THE DISTRIBUTION DEVICE

The invention relates to a dispensing device for the metered dispensing of a liquid gas formulation according to the preamble of independent claim 1 and to a method for producing such a dispensing device according to the preamble of independent claim 7.

For nail drifters with a linear internal combustion engine injection systems are generally used in the form of two-chamber aerosol dispensers. These two-chamber aerosol packages are filled in a first chamber with a standing under pressure combustible liquefied gas formulation as Nutzinhalt. By flexible or movable partitions separated from the payload is located in a second chamber of the aerosol packs also standing under overpressure propellant gas or propellant mixture, which ensures that the liquid gas formulation remains until the complete emptying under sufficiently high Überduck. The aerosol dispensers are equipped with a metering valve, with a precisely metered amount of the liquid gas formulation being dispensed per actuation thereof.

One problem with such aerosol packages used as an injection system is storage. Upon prolonged storage, the required working pressure of the liquefied gas formulation drops due to diffusion effects, so that the function of the aerosol dispenser or the then equipped with her nail driller is impaired. In principle, this problem could be solved by more complex construction and appropriate choice of construction materials. But this is contrary to the fact that such aerosols are needed in very large quantities and the construction and material costs must therefore be kept extremely low for economic reasons. In addition, the filling of the

Aerosol cans with liquid gas formulation and propellant can be done with the least possible effort.

By the present invention, this problem is now solved and a dispensing device of the generic type be improved to the effect that it can be produced and filled with extremely low design effort and can still be stored long without pressure loss. The solution of this problem underlying the invention consists in the design of the dispensing device according to the characterizing features of the independent claim 1. The inventive method for producing the dispensing device results from the characterizing features of independent claim. 7

Further expedient and particularly advantageous embodiments of the invention are the subject of the dependent claims.

The essence of the dispensing device according to the invention consists in the following: The device for the metered dispensing of a liquefied gas formulation comprises a pressure-stable container with a flanged rim on which a valve cover containing a dispensing valve is tightly fastened. The container is provided with two separate chambers, one receiving the liquid gas formulation and communicating with the dispensing valve and the other containing pressurized propellant. In the container, a substantially sealingly movable piston is provided, which divides the container into the two chambers. The driving medium (L) is compressed air in combination with a comparatively small amount (F _ü ) of liquefied gas formulation. The beaded edge (2) of the container (1) is formed as an inner crimp. The piston is adapted to permit overflow of liquefied gas formulation between the chambers in the direction from the chamber containing the liquefied gas formulation into the chamber containing the propellant medium. Due to the possibility of transfer between the chambers, the liquid gas formulation can be introduced into the propellant chamber in a simple and cost-effective manner.

Preferably, the upper side of the piston facing the valve cover is adapted in shape to the valve cover with the dispensing valve inserted therein. As a result, a virtually complete emptying of the device is achieved.

Advantageously, the piston is equipped with a one-way valve arrangement which allows an overflow of liquefied gas formulation from the chamber containing the liquefied gas formulation into the chamber containing the propellant medium of the container. The one-way valve arrangement is preferably by an elastic applied to the container inner wall Cylinder lip of the piston or formed by a piston provided in the check valve.

Further, it is advantageous if the valve cover is sealed with the beaded edge by a sealant made of a cured plastic material.

The essence of the inventive method lies in the following: For the preparation of a dispenser for a liquefied gas formulation, which dispenser has a pressure-stable container with a flanged edge on which a dispensing valve-containing valve cover is tightly mounted, wherein the container is equipped with two separate chambers, one of which receives the liquefied gas formulation and communicates with the dispensing valve and the other contains a pressurized propellant medium, the piston is introduced into the initially open and not yet provided with the flanged container to just below the opening edge, which compresses the air in the container becomes. Then the opening edge is crimped inwards, thus creating the bead. The valve cover is then fastened tightly with the dispensing valve inserted in it on the bead and thus closed the container. The container is filled through the dispensing valve with a predetermined amount of liquid gas formulation, wherein the piston is displaced towards the container bottom and thereby the compressed air between it and the container bottom compressed air is further compressed. Then, the container is temporarily heated with the liquid gas formulation in it, whereby the liquid gas formulation expands and a small amount of the liquid gas formulation flows into the chamber containing the compressed air between the piston and the container bottom.

Advantageously, the piston is initially introduced only to the extent that it closes the container in the initially open and not yet provided with the flanged edge container. Then compressed air with a predetermined pressure is introduced into the container. Subsequently, the piston is further inserted just below the opening edge of the container in the container.

In the following the invention will be explained in more detail with reference to an embodiment shown in the drawing. In the drawing show: - A -

Fig. 1-20 axial sections through the inventive dispensing device in different phases during their production by the inventive method and

21 shows an axial section through the dispensing device according to the invention in a ready-made and filled state.

The dispensing device according to the invention shown in FIG. 21 comprises a substantially cup-shaped, cylindrical container 1 which, at its (in the drawing) upper end, closes in a manner known per se by a valve cover 3 fastened tightly to a bead 2 with a dispensing valve 4 inserted therein is. The dispensing valve 4 may also be designed as a metering valve, as it is used by default in aerosol dispensers. In the container 1 is at the bottom of the container 1 upstanding a piston 5, which divides the interior of the container 1 and the dispenser into two chambers 6 and 7 and can slide in the container coaxially sealing. The piston 5 consists e.g. made of polyamide and comprising an inner cylinder part 5a, an annular ridge 5b and an outer cylinder lip 5 c, which is resiliently applied to the inner wall of the container 1 and is formed so that it forms a one-way valve assembly, which at sufficient pressure difference between them and the inner wall of the Container 1 allows the flow from the upper, the Ventüdeckeldeckelseitigen chamber 6 in the lower, bottom-side chamber 7, the flow in the opposite direction, however, blocks. Further details will be explained below in connection with the assembly of the dispenser. Alternatively, the piston 5 can also be equipped with a one-way valve, which allows an overflow from the chamber 6 into the chamber 7. Furthermore, the piston 5 is adapted at its upper side facing the valve cover 3 to the shape of the valve cover 3 with the dispensing valve 4 inserted therein, as can be seen particularly clearly from FIG. 14. As a result, a virtually complete emptying of the upper chamber 6 is achieved - see explanations below.

In the valve cover-side upper chamber 6 of the container 1 and the dispenser is as Nutzinhalt a combustible liquid gas formulation F, for example, about a butane-propane mixture. Under liquefied gas formulation F is understood in a conventional manner, a substance or mixture of substances which (s) is present in normal conditions in the gaseous phase, but at elevated pressure and / or correspondingly low temperature goes into the liquid phase. The liquid gas formulation F has, for example, at a temperature of 20 ° C, a partial pressure of 3.7 bar, at 50 ° C, a partial pressure of 7.0 bar.

In the separated by the piston 5 lower, bottom-side chamber 7 of the container 1 is located as a driving medium, an air cushion L with an overpressure of about 4.5 bar. Overpressure is the difference between the absolute pressure and the external air pressure. Further, located in the chamber 7, a small amount F _{u of} the liquid gas formulation whose partial pressure is superimposed on the pressure of the air cushion.

When the dispensing device 4 is taken in portions LPG formulation F during use by opening the metering valve, the piston 5 moves due to the overpressure of the air cushion L gradually to the valve cover 3 to. As a result, the lower chamber 7 increases and the pressure of the air cushion L decreases accordingly. The volumes of the two chambers 6 and 7 and the container 1 are dimensioned so that the air cushion still has a residual overpressure of about 0.5-0.8 bar when the piston 5 is present on the valve cover 3. As a result, a sufficient working pressure is ensured during the entire emptying of the chamber 6. Due to the form-fitting adjustment of the piston 5 to the valve cover 3 with the dispensing valve 4 used a virtually complete emptying is also guaranteed.

The container 1 is of course designed to be resistant to pressure so that it by the liquid gas formulation and the air cushion and the partial pressure of the

Liquefied gas formulation can withstand the internal pressure within the temperature range specified for storage and use of the dispenser (typically up to 12 bar overpressure).

The erfmdungsgemässe dispensing device is structurally inexpensive and can be prepared and filled according to another aspect of the invention in a particularly simple manner. The erfmdungsgemässe manufacturing method is explained below with reference to Figures 1-20.

First, the cup-shaped cylindrical container 1 is inserted into a support frame 100. The container 1 is not yet flanged at its opening edge (Fig. 1). Then, an annular centering tool 110 is positioned coaxially over the support frame 100 so that a relatively small gap a remains free between the centering tool and the support frame (FIG. 2 and enlarged detail illustration FIG. 3). The centering tool 110 engages with its lower part the container 1. The centering tool includes in its lower part an annular groove 111 and therein a sealing ring 112. Furthermore, it is with a radially outside of the sealing ring 112 into the annular groove 111 opening first air supply passage 113 and with an upper and radially inside the sealing ring 112 into the annular groove 111 opening second lo air supply channel 114 equipped. It can be about the circumference of the

Centering tool 110 may also be provided a plurality of first and second air supply channels. The piston 5 is inserted into the centering tool 110 so far that the lower edge of its cylinder lip 5 c is at the level of the opening edge of the container 1.

I ₅

Thereupon, compressed air is applied through the air supply passage 113, whereby the sealing ring 112 is pressed radially inwards and seals with the outer wall of the container 1 (FIG. 4 and enlarged detailed view of FIG. 5). Thereafter, compressed air can optionally be introduced through the air supply channel 0 114 into the interior of the container 1 below the piston 5 in a pre-gasification step.

Subsequently, the piston 5 is displaced axially into the container 1 by means of a punch 120, until the upper edge of its cylinder lip 5c lies slightly below the opening edge of the container 1. The air in the container 1 is already slightly (further) compressed (FIG. 6).

In the next step, the centering tool 110 is placed completely on the support frame 100 (FIG. 7 and enlarged detailed view of FIG. 8). At this time, the opening edge of the container 1 is separated from a conical chamfer 115 of FIG

Centering tool 110 deformed inwardly, so that a slight inner flange 2a is formed.

Then the centering tool 110 is removed. Due to the overpressure im5 container 1 while the piston 5 moves upward until the upper edge of his

Cylinder lip 5c on the inner flange 2a is present (Fig. 9). The piston 5 is retained by the slight inner flange 2a in the container 1. Located in the container 1 In this production phase, only the compressed air with an overpressure of about 0.5- 0.8 bar.

Subsequently, by means of a metering needle 130, a measured amount of a self-curing sealant E, e.g. an epoxy resin, in the space between the inner cylinder part 5 a and the cylinder lip 5 c of the piston 5 is introduced (Fig. 10). Alternatively, this step can also be carried out before the piston 5 is inserted into the container 1.

Then, a beading tool 140 is placed on the container rim and pressed down to the support frame 100 (FIG. 11 and enlarged detail view of FIG. 12). In this case, the piston is slightly shifted down into the container 1 and the already slightly flared opening edge of the container 1 to a complete inner flange (rolled edge) 2 deformed. The crimping tool 140 is then removed again.

Thereafter, a valve cover 3 is placed with a discharge valve 4 sealingly received therein on the beaded edge 2 of the container 1 (FIG. 13). To improve the tightness, a sealing ring can also be provided in a manner known per se between the valve cover 3 and the flanged edge 2. The valve cover 3 is then firmly connected by means of a clinch tool 150 in a conventional manner with the container 1 (enlarged detail of FIG. 14).

Subsequently, the container 1 provided with the valve cover 3 and the discharge valve 4 enclosed therein is positioned upside down in a transporting pack 160 (FIG. 15 and enlarged detail view of FIG. 16). The transport package 160 is formed in practice for receiving a plurality of containers 1. The first still flowable sealant E flows to the bead 2 and seals it after a curing time of e.g. about 24 hours against the valve cover 3 from. In the transport package 160, the container 1 is brought to the bottling, which is usually carried out by another company than the production of the ready-to-fill container. If the filling is to take place temporally immediately after the production of the container itself, the seal by means of the self-curing sealant E can also be omitted.

The following steps concern the filling of the dispenser with the liquefied gas formulation F. The container 1 provided with the valve cover 3 and the discharge valve 4 enclosed therein is placed in a receiving device 170 (FIG. 17). Then, a known per se filling tool 180 with the valve cover 2 in sealing contact

5 and introduced through the dispensing valve 4 in a conventional manner, a measured amount of liquid gas formulation F in the container 1 (Fig. 18). In a conventional container size (typically 105 ml less the volume of the piston 5), the filling amount, for example, 43.5 g corresponding to about 81 ml (in normal conditions). The piston 5 is moved down until

10 he finally stands up at the bottom of the container (Fig. 19). The air under the piston is thereby further compressed to typically about 5-6, in particular about 4.5 bar. The container 1 is divided by the piston 5 into two chambers 6 and 7, of which the upper chamber 6 connected to the dispensing valve contains the liquid gas formulation F and the chamber located below the piston

I ₅ 7 initially only the acting as a propellant compressed air L contains. The

Volume of the lower chamber 7 is typically about 25 ml with piston standing up on the container bottom.

In a final step, the finished container is subjected to a statutory 0 prescribed safety test. The filled container is placed in a bath 190 with warm water of a temperature of typically 50 ° C (Fig. 20). The partial pressure of the typically used butane-propane liquefied petroleum gas formulation F is about 3.7 bar at 20 ° C, about 7 bar at 50 ° C. The LPG formulation F expands by about 7% due to the heating, with a relatively small part F _u of typically about 3.5 g from the chamber 6 between the

Inner wall of the container 1 and the cylinder lip 5c of the piston 5 in the lower, the compressed air L containing chamber 7 flows over. In this case, the overpressure of the air L is superimposed on the partial pressure of the liquid gas formulation F _ü in the lower chamber 7. In the upper chamber 6 remain about 40 g Flüssiggasformulierung0 F.

Finally, when the filled container is removed from the water bath, it cools down and the volume of liquid gas formulation F in the upper chamber 6 shrinks again. The piston 5 moves _{5 in} accordance with something upwards. The dispenser is now ready to use (Figure 21). The small amount of liquid gas formulation F _ü in the propellant chamber 7 ensures that there is always a sufficiently high overpressure and the dispenser can be completely emptied in this way. The introduction of this small amount of liquid gas formulation F _ü in the propellant chamber according to the invention in connection with the anyway required

Safety testing of the dispensing device made so that no separate process steps are needed.

The dispensing device according to the invention is distinguished by a particularly simple and cost-effective method of production. In addition, it has a virtually unlimited shelf life, since the propellant is tightly enclosed and can not diffuse through any leaks between the valve cover and container edge away. The functionality of the dispenser is therefore subject to virtually no time limit. Diffusion losses can arise at most in the liquefied gas formulation, but this does not affect the functionality itself.

Claims

claims

1. A device for the metered dispensing of a liquid gas formulation with a pressure-stable container (1) with a flanged edge (2) on which a dispensing valve (4) containing valve cover (3) is tightly fastened, wherein the container (1) with two separate chambers ( 6.7), one of which receives the liquid gas formulation (F) and communicates with the dispensing valve (4) and the other of which contains a pressurized propellant medium (L), characterized in that in the container (1) a substantially sealingly movable Piston (5) is provided, which divides the container into the two chambers (6,7) that the driving medium (L) compressed air in combination with a comparatively small amount (F _ü ) of LPG formulation is that the beaded edge (2) of the Container (1) is formed as an inner flanging, and that the piston (5) is designed so that it is an overflow of liquid gas formulation (F) between the chambers (6,7) in the direction of the Fl allows ssiggasformulierung (F) containing chamber (6) in which the propellant (L, F _ü) containing chamber (7).

2. Apparatus according to claim 1, characterized in that the valve cover (3) facing the upper side of the piston (5) is adapted to the form of the valve cover (3) with the dispensing valve (4) inserted therein.

3. Device according to one of the preceding claims, characterized in that the piston (5) is equipped with a one-way valve assembly (5c) which an overflow of liquid gas formulation (F) of the liquid gas formulation (F) containing chamber (6) in the Driving medium (L, F _ü ) containing chamber (7) of the container (1) allows.

4. Apparatus according to claim 3, characterized in that the one-way valve arrangement is formed by an elastically on the container inner wall fitting cylinder lip (5 c) of the piston (5).

5. Apparatus according to claim 3, characterized in that the one-way valve arrangement is formed by a in the piston (5) provided check valve.

6. Device according to one of the preceding claims, characterized in that the valve cover (3) with the beaded edge (2) by a sealing compound (E) is sealed from a cured plastic material.

7. A method for producing a dispensing device for a liquefied petroleum gas formulation, which dispenser comprises a pressure-stable container (1) with a flanged edge (2) on which a valve cover (3) containing a dispensing valve (4) is tightly fastened, wherein the container (1) is equipped with two separate chambers (6,7), one of which receives the liquid gas formulation (F) and communicates with the dispensing valve (4) and the other of which contains a pressurized propellant (L), characterized in that the piston (5) in the initially open and not yet provided with the beaded container (1) is introduced to just below the opening edge, whereby the air in the container (1) is compressed, that the opening edge flanged inwards and so the bead (2) produced is that the valve cover (3) with the dispensing valve (4) inserted in it tightly mounted on the bead (2) and thus closed the container (1) in that the container (1) is filled with a predetermined amount of liquid gas formulation (F) through the dispensing valve (4), whereby the piston (5) is displaced towards the container bottom, thereby further compressing the compressed air trapped between it and the container bottom, and in that the container (1) with the liquid gas formulation (F) in it is temporarily heated, whereby the liquid gas formulation (F) expands and a small amount (F _ü ) of the liquid gas formulation into the chamber (7) containing the compressed air (L) overflowed between the piston (5) and the container bottom.

8. The method according to claim 7, characterized in that the piston (5) in the initially still open and not yet provided with the beaded container (1) is initially introduced only to the extent that it closes the container that in the container (1 ) Compressed air (L) is introduced with a predetermined overpressure and that then the piston (5) to just below the opening edge of the container (1) is inserted further into the container.

9. The method according to any one of claims 7-8, characterized in that the beaded rim (2) and attached to it the valve cover (3) by means of a flowable and self-curing sealant (E) are sealed.